Caroline R Sussman, Heather L Holmes, Alison Stiller, Ka Thao, Adriana V Gregory, Deema Anaam, Ryan Meloche, Yaman Mkhaimer, Harrison H Wells, Luiz D Vasconcelos, Matthew W Urban, Slobodan I Macura, Peter C Harris, Timothy L Kline, Michael F Romero
{"title":"Robotic Ultrasound and Novel Collagen Analyses for Polycystic Kidney Disease Research Using Mice.","authors":"Caroline R Sussman, Heather L Holmes, Alison Stiller, Ka Thao, Adriana V Gregory, Deema Anaam, Ryan Meloche, Yaman Mkhaimer, Harrison H Wells, Luiz D Vasconcelos, Matthew W Urban, Slobodan I Macura, Peter C Harris, Timothy L Kline, Michael F Romero","doi":"10.34067/KID.0000000000000542","DOIUrl":null,"url":null,"abstract":"<p><strong>Background: </strong>3D imaging and histology are critical tools for assessing polycystic kidney disease ( PKD ) in patients and animal models. Magnetic resonance ( MR ) imaging provides micron resolution, but is time consuming, expensive, and access to equipment and expertise is limiting. Robotic ultrasound ( US ) imaging has lower spatial resolution but is faster, more cost effective, and accessible. Similarly, Picrosirius red ( PSR ) staining and brightfield microscopy is commonly used to assess fibrosis; however, alternative methods have been shown in non-kidney tissues to provide greater sensitivity and more detailed structural characterization.</p><p><strong>Methods: </strong>In this study, we evaluated the utility of robotic US and alternative methods of quantifying PSR staining for PKD research. We compared longitudinal total kidney volume ( TKV ) measurements using US and MR. We additionally compared PSR imaging and quantification using standard brightfield with that by circularly polarized light with hue analysis, and fluorescence imaging analyzed using CT-FIRE software for automatic detection of individual collagen fibers.</p><p><strong>Results: </strong>Increased TKV was detected by US in Pkd1RC/RC vs wild type ( WT ) at timepoints spanning early to established disease. US inter-observer variability was greater but allowed scanning in 2-5 minutes/mouse while MR required 20-30 minutes/mouse. While no change in fibrotic index was detected in this cohort of relatively mild disease using brightfield, polarized light showed fibers skewed thinner in Pkd1RC/RC vs WT. Fluorescence imaging showed a higher density of collagen fibers in Pkd1RC/RC vs WT, and fibers were thinner and curvier with no change in length. Additionally, fiber density was higher in both glomeruli and tubules in Pkd1RC/RC , and glomeruli had a higher fiber density than tubules in Pkd1RC/RC , and trended higher in WT.</p><p><strong>Conclusions: </strong>These studies show robotic ultrasound is a rigorous imaging tool for pre-clinical PKD research. Additionally, they demonstrate the increased sensitivity of polarized and fluorescence analysis of PSR-stained collagen.</p>","PeriodicalId":17882,"journal":{"name":"Kidney360","volume":null,"pages":null},"PeriodicalIF":3.2000,"publicationDate":"2024-08-12","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":"0","resultStr":null,"platform":"Semanticscholar","paperid":null,"PeriodicalName":"Kidney360","FirstCategoryId":"1085","ListUrlMain":"https://doi.org/10.34067/KID.0000000000000542","RegionNum":0,"RegionCategory":null,"ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":null,"EPubDate":"","PubModel":"","JCR":"Q1","JCRName":"UROLOGY & NEPHROLOGY","Score":null,"Total":0}
引用次数: 0
Abstract
Background: 3D imaging and histology are critical tools for assessing polycystic kidney disease ( PKD ) in patients and animal models. Magnetic resonance ( MR ) imaging provides micron resolution, but is time consuming, expensive, and access to equipment and expertise is limiting. Robotic ultrasound ( US ) imaging has lower spatial resolution but is faster, more cost effective, and accessible. Similarly, Picrosirius red ( PSR ) staining and brightfield microscopy is commonly used to assess fibrosis; however, alternative methods have been shown in non-kidney tissues to provide greater sensitivity and more detailed structural characterization.
Methods: In this study, we evaluated the utility of robotic US and alternative methods of quantifying PSR staining for PKD research. We compared longitudinal total kidney volume ( TKV ) measurements using US and MR. We additionally compared PSR imaging and quantification using standard brightfield with that by circularly polarized light with hue analysis, and fluorescence imaging analyzed using CT-FIRE software for automatic detection of individual collagen fibers.
Results: Increased TKV was detected by US in Pkd1RC/RC vs wild type ( WT ) at timepoints spanning early to established disease. US inter-observer variability was greater but allowed scanning in 2-5 minutes/mouse while MR required 20-30 minutes/mouse. While no change in fibrotic index was detected in this cohort of relatively mild disease using brightfield, polarized light showed fibers skewed thinner in Pkd1RC/RC vs WT. Fluorescence imaging showed a higher density of collagen fibers in Pkd1RC/RC vs WT, and fibers were thinner and curvier with no change in length. Additionally, fiber density was higher in both glomeruli and tubules in Pkd1RC/RC , and glomeruli had a higher fiber density than tubules in Pkd1RC/RC , and trended higher in WT.
Conclusions: These studies show robotic ultrasound is a rigorous imaging tool for pre-clinical PKD research. Additionally, they demonstrate the increased sensitivity of polarized and fluorescence analysis of PSR-stained collagen.